Generally, a built-in evaporator is used to generate cold air in an air-cooled refrigerator. The cold air circulates through an air duct to various storage compartments of the refrigerator to implement refrigeration. The performance of preserving food freshness of the air-cooled refrigerator greatly depends on whether air flow circulation is appropriate in the storage compartments. If the cold air flows randomly along the air duct, the amount of air that enters each storage compartment tends to be excessive or insufficient, resulting in uneven temperature distribution in the storage compartments and reduced running efficiency of the refrigerator. Therefore, it is necessary to perform precise flow direction distribution and flow rate control on cold air that enters the storage compartments.
Similarly, in order to optimize storage spaces, a single storage compartment may generally be separated into a plurality of subdivided storage spaces by shelving devices such as shelves or drawers, and according to the amount of stored articles, the refrigerating capacity required for each of the storage spaces also varies. Therefore, cold air directly entering the storage compartment from a certain place of the storage compartment without control may cause the problem that some of the storage spaces are overcooled and some suffer from insufficient refrigerating capacity.
For this, a branching air supply device is disposed at an air duct in the back of a box of a refrigerator in the prior art. An air inlet of the branching air supply device is connected to a cold air inlet, a plurality of air outlets of the branching air supply device are respectively connected to a plurality of cold air outlets of various storage compartments, and a control apparatus (for example, an electrical air damper) is disposed at the air duct to control the cold air inlet and the cold air outlets to be opened or closed. However, when this branching air supply device is turned off, the electrical air damper of the branching air supply device cannot be completely closed because of an angle. As a result, a storage compartment is overcooled, and the energy consumption of the refrigerator is increased. The use of the electrical air damper contributes to the structural complexity of the branching air supply device and increases the power consumption of the refrigerator.